1. Field of the Invention
The invention concerns a thrust-vectoring nozzle for a jet propulsion system including a fixed part solid with the propulsion system on which is articulated a pivoting part, a sealing member arranged between the two parts, and jacks controlling the movement of the pivoting part.
2. Description of the Prior Art
The criteria for agility required of modern military planes sometimes forces the air-frame designer to have recourse to means other than aerodynamic control surfaces in order to achieve rapid trim changes.
One of the most effective means is to provide the jet with a thrust-vectoring nozzle making it possible to achieve, depending on the deflection component selected, either a lateral sideslip of the craft or a rapid tail downward movement without a correlative increase in drag due to the lifting of the elevons. However, nozzles steerable on all axes require either a double articulation or a single articulation and a rotating connection. These devices are cumbersome and pose delicate tightness problems.
U.S. Pat. No. 3,182,452 gives a simple and relatively noncumbersome realization of a rocket nozzle. The chamber outlet creates a wide spherical boss against which a corresponding spherical boss provided on the nozzle slides. Tightness is assured by a hollow O-ring having an open circular section, the edges of the section being fixed onto the chamber and the nozzle. Rotation of the nozzle is obtained by four jacks arranged according to the perpendicular diameters of the chamber and the nozzle.
The shape and size of the chamber outlet allow correct centering and holding of the nozzle, which is not the case with propulsion systems and airplane nozzles in which the diameters of the fixed nozzle and the mobile nozzle are essentially equal.